Month: March 2010

Continuing my HTML5 and canvas experiments, I’ve put together a generative music system. Essentially, a series of particles move across a field, occasionally triggering sounds — the sound triggered depends on their location in the field.

There is, of course, a little bit more to it than that. Under the hood, I’ve got a series of HTML5 Audio objects that are used to provide polyphonic audio using a simple round-robin algorithm (I encoded the audio in OGG, so you’ll need to use an OGG-friendly browser, like Firefox). The particles are much simpler than those in my previous canvas dalliance, in that they don’t swarm, and their motion is more linear.

I’ve been meaning to start playing with the HTML5 <canvas> element for a while now, and yesterday I took the opportunity. I translated a Processing sketch I made a while ago into JavaScript (with a few minor enhancements).

Essentially, 1 to 3 swarms of particles move around the canvas, reproducing when the conditions are just right, and dying of old age. Quite simple, but the patterns produced can be really quite pretty.

One interesting thing that I discovered whilst doing this is that you can’t pass around a canvas’ context at the instantiation of a MooTools class — it complains about wrapped natives. That’s why, if you like in the source JavaScript, you’ll see me pass the actual context around to various functions. I’d be interested in hearing if anyone has a workaround for this, because this is, well, a bit clunky.